[Bug fortran/77327] AddressSanitizer: heap-use-after-free gcc-trunk-239276/gcc/fortran/interface.c:403 in compare_components

["fritzoreese at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77327

--- Comment #7 from Fritz Reese <fritzoreese at gmail dot com> ---
(In reply to Vittorio Zecca from comment #5)
> The test case you propose, dec_structure_13.f90, does not trigger the asan
> memory checker.
Sorry if it was unclear, the new testcase dec_structure_13.f90 tests a separate
regression that is also fixed by the patch (see the comments in my post on the
mailing list).

(In reply to Vittorio Zecca from comment #5)
> (In reply to Fritz Reese from comment #3)
> > I would appreciate
> > ideas for a testcase I can commit with the aforementioned patch to
> > ensure this PR isn't regressed.
> As I wrote before, the test case gfortran.dg/import4.f90 does trigger
> the asan memory checker.
Is that sufficient then to test the regression, or need I add another testcase
to my patch?

(In reply to Vittorio Zecca from comment #5)
> In your test case I do not understand the final statement "call
> sub2(u2)" because
> sub2 is not defined.
That is a typo - "sub3" from dec_structure_13.f90 line 40 should be named
"sub2". That's what I get for forgetting "implicit none"...

(In reply to Vittorio Zecca from comment #6)
> Fritz, do you have a -fsanitize=address version of gfortran, in
> particular of f951?
I was not aware of the capability. I will build one.